$\pt$-differential production cross section of prompt $\Dzero$ mesonswith $|y|< 0.5$ in the interval \mbox{$0< \pt< 36~\gev/c$}, in pp collisions at$\sqrt s =7~\tev$ The data point in $0< \pt< 1~\gev/c$ is obtained from the analysis without decayvertex reconstruction described in Ref.~ The cross section is compared to three pQCD calculations:FONLL~ (top-left panel), GM-VFNS~(top-right panel) and a leading order (LO) calculation based on$k_{\rm T}$-factorisation~ (bottom panel) The ratios of the data to the three calculated cross sections are shownin the lower part of each panel. In the data-to-theory ratios the 3.5\%normalisation uncertainty due to the luminosity determination is not includedin the systematic uncertainty on the data points | |